Apparatus for echo distance measurement



Jan. 4, 1949. R.- E. PETERSON 2,458,415

APPARATUS FOR ECHO DISTANCE MEASUREMENT Original Filed Aug. 19, 1942 2 Sheets-Sheet 1 N uz Q 85% Q h x86 5 3 O a a S 0 q 0 W Lu) b2 2 M Lu Q? I u 2E Q g k W RELAV POWER POWE/Q TRANSFER I ('5 (D IIF g *5 Q T INVENTOI? Pose-RT E. PETERSON A TTORN E V Jan. 4, 1949. R. E. PETERSON 2,458,415

APPARATUS FOR ECHO DISTANCE MEASUREMENT Original Filed Aug. 19, 1942 2 Sheets-Sheet 2 lNVE/VTOI? P055101" 5. Pmresow PNE V Patented Jan. 4, 1949 I APPARATUS FOR ECHO DISTANCE MEASUREMENT Robert E. Peterson, Danvers, Mass., assignor to Submarine Signal Company, Boston, Mass., a corporation of Delaware Continuation of application Serial No. 455,391,

August 19, 1942. This application October 22, 1947, Serial No. 781,329

6 Claims. (Cl. 177-386) This is a continuation of my copending application, Serial No. 455,391, filed August 19, 1942, and forfeited.

The present invention relates to a distance measuring system which measures the distance as a function of thetime of travel of a wave in the medium from the transmitting station to the reflecting object and return.

The present invention is more particularly asing arrangement illustrated in the other figures.

In Fig. 1, l represents a projector which may be used face downward in the water for depth soundings or may have its face in a vertical plane and be rotated for sound ranging, the position of the unit being immaterial to the nature of the present invention. The transmitting signal is produced in the projector I through energy supplied by the oscillator 2 through .the output transformer 3 over the line 4, the power-transfer sociated with distance and depth measurement 19 relay 5 when the switch 6 is in the lower position in connection with submarine acoustic apparaand the line I to the projector I. This contus and finds its application in measurements nection may be a double line or, as illustrated by the use of compressional wave vibrations in in the figure, the projector and the oscillator the sonic and supersonic range in whicha single may be provided with ground returns 8 and 9. unit is used for sending and receiving. -The receiving circuit uses the propector I as the The invention finds its principal merit in the pickup unit from which the energy is conducted measurement of shallow depths and short disover the line I which connects with the line Ill tances. 7 either through the power-transfer relay 5 or the Principally in the use of sound waves, both cam-switching arrangement, the operation of sonic and supersonic for distance measurement, which will be explained below. The line l0 condifliculty has been experienced in measuring the nects to the receiver amplifier H which operates short distances. Where the transmitting and the indicator l2 (Fig. 2) which may be of the pickup unit is the same element, either the senddischarge tube type. The cams l3 and it are ing and receiving circuits must both be permadiagrammatically shown in Fig. 1, and in Fig. 2 nently connected to the same unit, in which case they are h wn in p p ive n the me S t special means must be employed to prevent the as the disc l5 carrying the indicator l2. The transmittted signal from aflecting the receiving cam 13 is provi with p phe l p i n circuit, or a switch element must be employed l6 which rides successively under the projections to switch from sending to receiving directly after l8 and IQ of the switch contacts 20 and 2|, rethe signal is sent out. In the past such switchspective first c os n t ta 0 d then ing from sending to receiving has itself afiected closing the contact 2|. The cam I4 is also prothe receiving circuit and delayed the full recovery vided with a p r her l Pro i n 2 i h as of the receiving circuit 50 as not to permit its it rides under the projections 23 and 24 closes proper and complete operation. the switch contacts 25 and 26, respectively, in One of the principal objects of the present inthe order set forth. As the projection 23 is vention is to provide a switch-transfer system moved outward on the cam, the contact 21 beso that the transfer from sending to receiving ins to p n- The m l3 With it asso iat d and from receiving to sending can be quietly contacts 20 and 2| control the energization of and eil'iciently effected at the desired moment the 001128 of the power-transfer relay. The two in the cycle of operation of the indicator sys- 40 switch contacts 20 and 2| are connected in series tem. This system is particularly useful for shalwith the coil 28 across the power supply, not low depth sounding and ranging apparatus emshown, so that the coil 28 is only energized whlle ploying supersonic transmitters and receivers of both contacts 20 and 2| are closed. This, it will the magnetostrictive or other supersonic types be seen, will occur for only the short time inand permits distance measurement to a fraction terval dependent upon the speed of the cam, of a fathom using a single unit for sending and length of are covered by It and angular spacing receiving. of projections l8 and I9, which factcrs deter- Without further describing the merits and admine the interval in which the two contacts vantages of the present invention, the invention 20 and 2| are simultaneously maintained closed. will be described in connection with the draw- When the coil 28 is energized, the switch conings, in which Fig. 1 shows a diagrammatic laytact arm 6 is drawn downward until the arm out of the system; Fig. 2 shows a perspective makes contact with the switch post 29, comof a detail of the invention; and Fig. 3 illustrates pleting the power circuit from the oscillator to the timing cycles in connection with the switchthe projector over the line 4 and the line 1.

The projector is then in a position to be keyed through the keying control circuit which is connected to the oscillator by means of the lines 30 and 3|. Keying of this circuit occurs during the interval that both switch contacts 25 and 26 are closed since both of these contacts are in series with the lines 30 and 3|. The switch 6 is closed just prior to the keying of the oscillator and remains closed for a short interval after keying. This will be explained below in connection with Fig. 3.

As the projection 22 on the cam l4 begins to close the contact 25, it opens the contact 21 which is connected by the lines 32 and 33 to the contact posts 34 and 35, respectively, in the power-transfer relay 5. The opening of contact 21 does not disconnect the receiving circuit from the projector since this occurs prior to the energizing of the coil 28 and the pulling down of switch 6. the operation of which transfers from receiving to sending. The release of the projection 23 ends the transmitting keying interval and completes the contact 21, closing the circuit between the posts 34 and 35 in the power-transfer relay over the lines 32 and 33, thus completing the receiving circuit from the projector through the cable I, the lines 32 and 33, the switch 21 to the line i and the receiver amplifier H. The switch 21 is closed prior to the release of the switch arm 6 and this adjustment may be accurately regulated by means of the set screw 36 for adjusting one contact of the pair of contacts 21. In the sequence of the opening of these various contacts, the contact 21 is opened prior to the operation of the coil 28 which pulls the switch arm 6 from a receiving to a sending position.

The sequence of operation is illustrated in the diagrammatic sketch of Fig. 3 showing the operation of the switching system in association with the measuring scale which is positioned in front of the indicator disc. The moment of transmission occurs when the indicator I 2 comes to the zero marking on the scale 40. During the interval indicated by the sectioned are A, the contact for operating the power-transfer relay remains closed. During the interval indicated by the sectioned arc B, the contact 2| remains closed so that the overlapping portions between the ends 12 and a is the time interval during which the power-transfer relay holds the arm 6 in a sending position. In a similar fashion the transmitter keying is produced when the contacts and 26 remain closed. The sectioned arc marked by C in Fig. 3 indicates the interval in which the switch 25 is closed and that marked by D indicates the interval in which the switch 26 is closed so that the overlapping interval d, c which is spaced between the overlapping interval b, a is the keying interval for the transmitter. The unsectioned arc E indicates the portion of the cycle in which the receiving keying contact, that is the contact 21, is opened. This, it will be refunction is that between the line b and the line e,

and during this time the transmitted signal as represented by the interval between 41, c is being sent out.

Having now described my invention, I claim: 1. In a system for distance measurement by membered, occurs Just prior to closing of the conthe time-of-travel method, a single projecting and receiving unit, a source of projection power, a receiving circuit, transfer-switching means having a plurality of groups of switch contacts, a first of said groups of switch contacts connecting said source to said unit, a second of said groups of switch contacts connecting said receiving circuit to said unit, a keying circuit which energizes said source, a third of said groups of switch contacts completing said keying circuit, a distance indicator connected to the output of said receiving circuit and operating in a predetermined time sequence, said transfer-switching means also including operating means associated in operation with said indicator and operating said first group of switch contacts for a predetermined period, operating said third group of switch contacts during said period, and operating said second group of switch contacts just after the operation of said third group of switch contacts.

2. In a system for distance measurement by the time-of-travel method, a single projecting and receiving unit, a source of projection power, a receiving circuit, transfer-switching means having a plurality of groups of switch contacts, a first of said groups of switch contacts connecting said source to said unit, a second of said groups of switch contacts connecting said receiving circuit to said unit, a keying circuit which energizes said source, a third of said groups of switch contacts completing said keying circuit, a shunt connection across said second group of switch contacts having a normally closed switch contact therein, a distance indicator connected to the output of said receiving circuit and-operating in a predetermined time sequence, said indicator having associated therewith cam-operated means, said plurality of groups of switch contacts being positioned to be operated by said cam-operated means, said first group of' switch contacts being operated by said cam-operated means for a predetermined period, said third group of switch contacts being operated by said cam-operated means during said period, and said normally-closed switch contact being simultaneously disconnected by said cam-operated means, whereby the receiving circuit is disconnected from the unit for a time interval beginning just before to an instant just after the keying interval.

3. In a system for distance measurement by the time-of-travel method, a single projecting and receiving unit, a distance scale, a moving distance indicator operating in a predetermined time sequence which indicates distance with reference to said distance scale, a transmitter, a transfer relay switching means having a transmitting position in which it connects said transmitter to said unit, means operative in association with the'moving indicator and holding said relay in said transmitting position overlapping a signal interval, a keying circuit which energizes said transmitter, keying-means operative in association with the moving indicator and completing said keying circuit during the signal interval, a circuit normally connecting said unit to said indicator, and means associated with said keyingmeans and opening said circuit prior to the keying of the transmitter and closing said circuit just subsequent thereto.

4. In a system for distance measurement by the time-of-travel method, a single projecting and re-. ceiving unit, a distance scale, a rotating distance indicator which indicates distance with reference to said distance scale, cam means rotated in association with said indicator, a sending circuit, a

transfer relay switch connected to said unit and having a sending position and a receiving position, a transfer relay operating circuit, and a plurality of groups of switch-contact means operativeiy associated with said cam means, a first of said groups of switch contacts being series connected in said transfer relay circuit and operated by said cam means to operate said transfer relay to the sending position for a certain time interval, a second of said groups of switch contacts comprising two series connected sets of contacts arranged for sequential operation and completing said sending circuit when both sets of contacts are closed by said cam means, and a third of said groups of switch contacts in shunt connection across said receiving position, said third group of contacts being opened by said cam means simultaneously with the closing of the first set of said second group of contacts and being closed with the opening thereof, said second group of contacts completing their circuit during said time interval.

5. In a system for distance measurement by the time-of-travel method, a single projecting and receiving unit, a source of projection power, a receiving circuit, a distance indicator connected to the output of said receiving circuit and operating in a predetermined time sequence, a plurality of groups of switch contacts, a first of said groups of switch contacts connecting said source to said unit, a second of said groups of switch contacts connecting said receiving circuit to said unit, a keying circuit which energizes said source, a third of said groups of contacts completing said keying circuit, means associated in operation with said distance indicator and operating said first group of switch contacts for a certain period, operating said third group of switch contacts during said period, and operating said second group of switch contacts just after the operation of said third group of switch contacts.

6. In a system for distance measurement by the time-of-travel method, a single projecting and receiving unit, a source of projection power, a receiving circuit, a distance indicator connected to the output of said receiving circuit and operating in a predetermined time sequence, a pinrality of groups of switch contacts, a first oi. said groups of switch contacts connecting said source to said unit, a second of said groups 01' switch contacts connecting said receiving circuit to said unit, a keying circuit which energizes said source, a third of said groups of contacts completing said keying circuit, rotatable switch operator means operatively connected with said indicator and operating said first group of switch contacts for a certain period, operating said third group of switch contacts during said period, and operating said second group of switch contacts just after the operation of said third group of switch contacts.

REFERENCES crrEn The following references are of record in the file of this patents- UNITED S'I'A'I'ES PATENTS 

